Electric Propulsion System Optimization for Propeller Aircraft

This paper presents methods and results for modeling electric propulsion systems with the goal of trend identification and system performance optimization. Both propeller aerodynamic and electric circuit efficiencies are modeled to capture the propulsion system total performance in both static and forward flight operation. Propeller loads are modeled based on modeled torque curves at varying design RPMs. Motor performance is estimated from curve fits for the winding resistance and idle currents as a function of voltage constant based on manufacturer reported and lab measured data. Variations in combinations of motor design voltage constant and the propeller operating condition create a wide range of system efficiencies. System total efficiency data is presented for each configuration variant. The methods in this paper are expected to be directly applicable to propeller-driven electric aircraft design studies.